1. Field of the Invention
This invention concerns a method and apparatus for operational testing of electronic carbon monoxide detectors.
2. State of the Prior Art
Electronic carbon monoxide detectors are coming into widespread use and many such units have been installed by concerned home owners. Carbon monoxide is an odorless, colorless gas generated by certain combustion processes. For example, carbon monoxide frequently is an undesirably by-product of kerosene and fuel oil heaters, which if improperly vented to the outside atmosphere, can cause dangerous and occasionally lethal accumulations of carbon monoxide in an enclosed space. The unfortunate result is that every year many persons die from carbon monoxide poisoning. Installation of carbon monoxide detectors on premises which are at particular risk of accumulation of that gas can save lives by providing early warning of unusual levels of the gas before dangerous concentrations have a chance to build up. Recent advances in detector technology has brought about the commercial availability of compact, affordable electronic carbon monoxide detectors, suitable for home use.
A shortcoming of these carbon monoxide detectors is the lack of means for operationally testing these units, that is, testing the actual response of the electronic detector to the presence of carbon monoxide in the environment. Instead, the commercially available carbon monoxide detectors commonly are equipped with a test button which when actuated serves to verify the operation of the electronic circuits and of the audible or visual signaling system. This type of testing does not, however, verify the proper operation of the gas sensor element of the detector unit, i.e., the test does not verify that the gas sensor and associated detector circuits are capable of responding to the actual presence of carbon monoxide gas in the immediate environment. Clearly, this is a serious shortcoming as proper operation of the gas sensor element is critical to the usefulness of the detector unit as a whole. Proper operation of the remaining electronics and the audio signaling device is meaningless in the absence of a properly functioning gas sensor.
What is needed is a simple, inexpensive, and reliable method and apparatus for testing carbon monoxide detectors in such manner as to verify the proper operation and actuation of the carbon monoxide gas sensor in the presence of that gas in the immediate environment. Also, the desired method and apparatus should be safe and easy to implement by the ordinary home owner.